<!DOCTYPE html>
<html lang="en">
<head>
    <meta harset="UTF-8">
    <title>后代(子孙)选择器</title>
    <style type="text/css">
        #div1 p{
            color:blue;
        }
    </style>
</head>
<body>
    <div id="div1">
        <div >我是儿子div
            <div><p>我是孙子p</p></div>
        </div>
        <span>我是儿子span</span>
        <p>我是孙子p</p>
    </div>
</body>
</html>